Technical Field
The present invention is related to an alignment material, an alignment layer, a liquid crystal display device and a method for manufacturing the same.
Background Art
Currently, various kinds of flat panel displays are being developed. Among them, a liquid crystal display is a flat panel display that is extensively used for the most various purposes.
Liquid crystal displays, according to an arrangement state of liquid crystal and a driving manner, comprise a TN (twisted nematic) liquid crystal display, a VA (vertically aligned) liquid crystal display, an IPS (in-plane switching) liquid crystal display, an OCB (optically compensated bend) liquid crystal display, and the like. In these liquid crystal displays, the liquid crystal has a predetermined arrangement at an early stage due to effects of an alignment layer and intrinsic properties of the liquid crystal, and the arrangement of the liquid crystal is changed if an electric field is applied thereto due to an optical anisotropic property of the liquid crystal, a polarization state of light passing through the liquid crystal varies according to an arrangement state of the liquid crystal, and the difference is represented by a difference in amount of light transmitted through a polarizer to display an image.
The alignment that determines an initial arrangement of the liquid crystal is mostly performed by rubbing the alignment layer in a predetermined direction using a rubbing method. However, since the rubbing method is mechanically performed, it is difficult to precisely control the initial alignment state of the liquid crystal and provide different pre-tilts for each fine region.
To solve the problems described above, there may be provided a photoalignment method that aligns the liquid crystal in a particular direction by way of irradiation. Nevertheless, in case the photoalignment method is used, the alignment may also be deteriorated because anchoring energy required is not sufficient enough.